def test_parallel_walk_inconsistent_trees(self):
node_1 = parsing.parse_str(
textwrap.dedent("""
def f(a):
return a + 1
"""))
node_2 = parsing.parse_str(
textwrap.dedent("""
def f(a):
return a + (a * 2)
"""))
node_3 = parsing.parse_str(
textwrap.dedent("""
def f(a):
return a + 2
"""))
with self.assertRaises(ValueError):
for _ in ast_util.parallel_walk(node_1, node_2):
pass
# There is not particular reason to reject trees that differ only in the
# value of a constant.
# TODO(mdanatg): This should probably be allowed.
with self.assertRaises(ValueError):
for _ in ast_util.parallel_walk(node_1, node_3):
pass
def replace(template, **replacements):
"""Replaces placeholders in a Python template.
AST Name and Tuple nodes always receive the context that inferred from
the template. However, when replacing more complex nodes (that can potentially
contain Name children), then the caller is responsible for setting the
appropriate context.
Args:
template: A string representing Python code. Any symbol name can be used
that appears in the template code can be used as placeholder.
**replacements: A mapping from placeholder names to (lists of) AST nodes
that these placeholders will be replaced by. String values are also
supported as a shorthand for AST Name nodes with the respective ID.
Returns:
An AST node or list of AST nodes with the replacements made. If the
template was a function, a list will be returned. If the template was a
node, the same node will be returned. If the template was a string, an
AST node will be returned (a `Module` node in the case of a multi-line
string, an `Expr` node otherwise).
Raises:
ValueError: if the arguments are incorrect.
"""
if not isinstance(template, str):
raise ValueError('Expected string template, got %s' % type(template))
tree = parsing.parse_str(textwrap.dedent(template))
for k in replacements:
replacements[k] = _convert_to_ast(replacements[k])
results = ReplaceTransformer(replacements).visit(tree).body
if isinstance(results, list):
return [qual_names.resolve(r) for r in results]
return qual_names.resolve(results)
def test_subscript_resolve(self):
samples = """
x[i]
x[i.b]
a.b[c]
a.b[x.y]
a[z[c]]
a[b[c[d]]]
a[b].c
a.b.c[d].e.f
a.b[c[d]].e.f
a.b[c[d.e.f].g].h
"""
nodes = qual_names.resolve(parsing.parse_str(textwrap.dedent(samples)))
nodes = tuple(n.value for n in nodes.body)
self.assertQNStringIs(nodes[0], 'x[i]')
self.assertQNStringIs(nodes[1], 'x[i.b]')
self.assertQNStringIs(nodes[2], 'a.b[c]')
self.assertQNStringIs(nodes[3], 'a.b[x.y]')
self.assertQNStringIs(nodes[4], 'a[z[c]]')
self.assertQNStringIs(nodes[5], 'a[b[c[d]]]')
self.assertQNStringIs(nodes[6], 'a[b].c')
self.assertQNStringIs(nodes[7], 'a.b.c[d].e.f')
self.assertQNStringIs(nodes[8], 'a.b[c[d]].e.f')
self.assertQNStringIs(nodes[9], 'a.b[c[d.e.f].g].h')
def test_parse_str(self):
mod = parsing.parse_str(
textwrap.dedent("""
def f(x):
return x + 1
"""))
self.assertEqual('f', mod.body[0].name)
def test_parallel_walk(self):
node = parsing.parse_str(
textwrap.dedent("""
def f(a):
return a + 1
"""))
for child_a, child_b in ast_util.parallel_walk(node, node):
self.assertEqual(child_a, child_b)
def test_keywords_to_dict(self):
keywords = parsing.parse_expression('f(a=b, c=1, d=\'e\')').keywords
d = ast_util.keywords_to_dict(keywords)
# Make sure we generate a usable dict node by attaching it to a variable and
# compiling everything.
node = parsing.parse_str('def f(b): pass').body[0]
node.body.append(ast.Return(d))
result, _ = parsing.ast_to_object(node)
self.assertDictEqual(result.f(3), {'a': 3, 'c': 1, 'd': 'e'})
def test_rename_symbols_attributes(self):
node = parsing.parse_str('b.c = b.c.d')
node = qual_names.resolve(node)
node = ast_util.rename_symbols(
node, {qual_names.from_str('b.c'): qual_names.QN('renamed_b_c')})
source = parsing.ast_to_source(node)
self.assertEqual(source.strip(), 'renamed_b_c = renamed_b_c.d')
def test_rename_symbols_annotations(self):
node = parsing.parse_str('a[i]')
node = qual_names.resolve(node)
anno.setanno(node, 'foo', 'bar')
orig_anno = anno.getanno(node, 'foo')
node = ast_util.rename_symbols(node,
{qual_names.QN('a'): qual_names.QN('b')})
self.assertIs(anno.getanno(node, 'foo'), orig_anno)
def test_rename_symbols_basic(self):
node = parsing.parse_str('a + b')
node = qual_names.resolve(node)
node = ast_util.rename_symbols(
node, {qual_names.QN('a'): qual_names.QN('renamed_a')})
self.assertIsInstance(node.body[0].value.left.id, str)
source = parsing.ast_to_source(node)
self.assertEqual(source.strip(), 'renamed_a + b')
def test_apply_to_single_assignments_static_unpack(self):
node = parsing.parse_str('a, b, c = d, e, f')
node = node.body[0]
ast_util.apply_to_single_assignments(node.targets, node.value,
self._mock_apply_fn)
self.assertDictEqual(self._invocation_counts, {
('a', 'd'): 1,
('b', 'e'): 1,
('c', 'f'): 1,
})
def test_copy_clean_preserves_annotations(self):
node = parsing.parse_str(
textwrap.dedent("""
def f(a):
return a + 1
"""))
anno.setanno(node.body[0], 'foo', 'bar')
anno.setanno(node.body[0], 'baz', 1)
new_node = ast_util.copy_clean(node, preserve_annos={'foo'})
self.assertEqual(anno.getanno(new_node.body[0], 'foo'), 'bar')
self.assertFalse(anno.hasanno(new_node.body[0], 'baz'))
def test_copy_clean(self):
node = parsing.parse_str(
textwrap.dedent("""
def f(a):
return a + 1
"""))
setattr(node.body[0], '__foo', 'bar')
new_node = ast_util.copy_clean(node)
self.assertIsNot(new_node, node)
self.assertIsNot(new_node.body[0], node.body[0])
self.assertFalse(hasattr(new_node.body[0], '__foo'))
def create_source_map(nodes, code, filename, indices_in_code):
"""Creates a source map between an annotated AST and the code it compiles to.
Args:
nodes: Iterable[ast.AST, ...]
code: Text
filename: Optional[Text]
indices_in_code: Union[int, Iterable[int, ...]], the positions at which
nodes appear in code. The parsing always returns a module when parsing
code. This argument indicates the position in that module's body at which
the corresponding of node should appear.
Returns:
Dict[CodeLocation, OriginInfo], mapping locations in code to locations
indicated by origin annotations in node.
"""
reparsed_nodes = parsing.parse_str(code)
reparsed_nodes = [reparsed_nodes.body[i] for i in indices_in_code]
resolve(reparsed_nodes, code)
result = {}
for before, after in ast_util.parallel_walk(nodes, reparsed_nodes):
# Note: generated code might not be mapped back to its origin.
# TODO(mdanatg): Generated code should always be mapped to something.
origin_info = anno.getanno(before, anno.Basic.ORIGIN, default=None)
final_info = anno.getanno(after, anno.Basic.ORIGIN, default=None)
if origin_info is None or final_info is None:
continue
line_loc = LineLocation(filename, final_info.loc.lineno)
existing_origin = result.get(line_loc)
if existing_origin is not None:
# Overlaps may exist because of child nodes, but almost never to
# different line locations. Exception make decorated functions, where
# both lines are mapped to the same line in the AST.
# Line overlaps: keep bottom node.
if existing_origin.loc.line_loc == origin_info.loc.line_loc:
if existing_origin.loc.lineno >= origin_info.loc.lineno:
continue
# In case of overlaps, keep the leftmost node.
if existing_origin.loc.col_offset <= origin_info.loc.col_offset:
continue
result[line_loc] = origin_info
return result
def test_function_calls(self):
samples = """
a.b
a.b()
a().b
z[i]
z[i]()
z()[i]
"""
nodes = qual_names.resolve(parsing.parse_str(textwrap.dedent(samples)))
nodes = tuple(n.value for n in nodes.body)
self.assertQNStringIs(nodes[0], 'a.b')
self.assertQNStringIs(nodes[1].func, 'a.b')
self.assertQNStringIs(nodes[2].value.func, 'a')
self.assertQNStringIs(nodes[3], 'z[i]')
self.assertQNStringIs(nodes[4].func, 'z[i]')
self.assertQNStringIs(nodes[5].value.func, 'z')
def matches(node, pattern):
"""Basic pattern matcher for AST.
The pattern may contain wildcards represented by the symbol '_'. A node
matches a pattern if for every node in the tree, either there is a node of
the same type in pattern, or a Name node with id='_'.
Args:
node: ast.AST
pattern: ast.AST
Returns:
bool
"""
if isinstance(pattern, str):
pattern, = parsing.parse_str(pattern).body
matcher = PatternMatcher(pattern)
matcher.visit(node)
return matcher.matches
def test_resolve(self):
samples = """
a
a.b
(c, d.e)
[f, (g.h.i)]
j(k, l)
"""
nodes = qual_names.resolve(parsing.parse_str(textwrap.dedent(samples)))
nodes = tuple(n.value for n in nodes.body)
self.assertQNStringIs(nodes[0], 'a')
self.assertQNStringIs(nodes[1], 'a.b')
self.assertQNStringIs(nodes[2].elts[0], 'c')
self.assertQNStringIs(nodes[2].elts[1], 'd.e')
self.assertQNStringIs(nodes[3].elts[0], 'f')
self.assertQNStringIs(nodes[3].elts[1], 'g.h.i')
self.assertQNStringIs(nodes[4].func, 'j')
self.assertQNStringIs(nodes[4].args[0], 'k')
self.assertQNStringIs(nodes[4].args[1], 'l')
